Unlike DNA, RNA contains which nitrogenous base?

• A. Cytosine
• B. Thymine
• C. Uracil
• D. Adenine

Answer: (C)

Verified step by step guidance

1. Recall the four nitrogenous bases found in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G).
2. Understand that RNA is similar to DNA but has a key difference in one of its nitrogenous bases.
3. Identify that in RNA, thymine (T) is replaced by uracil (U), which pairs with adenine during base pairing.
4. Recognize that cytosine, adenine, and guanine are present in both DNA and RNA, but uracil is unique to RNA.
5. Conclude that the nitrogenous base found in RNA but not in DNA is uracil.